Treatment of Dissolved Perchlorate, Nitrate, and Sulfate Using Zero‐Valent Iron and Organic Carbon. Issue 3 (1st May 2014)

• Record Type: Journal Article
• Authors: Liu, YingYing; Ptacek, Carol J.; Blowes, David W.
• Is Part Of: Journal of Environmental Quality. Volume 43:Issue 3(2014)
• Page Start: 842
• Page End: 850
• Publication Date: 2014-05-01
• Subjects: Agricultural ecology -- Periodicals; Environmental engineering -- Periodicals; Pollution -- Periodicals; 630
• DOI: 10.2134/jeq2013.03.0077
• Languages: English
• ISSNs: 0047-2425

Abstract

Abstract : Waters containing ClO4 − and dissolved NO3 −, derived from detonated explosives and solid propellants, often also contain elevated concentrations of other dissolved constituents, including SO4 2− . Four column experiments, containing mixtures of silica sand, zero‐valent Fe (ZVI) and organic C (OC) were conducted to evaluate the potential for simultaneous removal of NO3 −, SO4 2− and ClO4 − . Initially, the flow rate was maintained at 0.5 pore volumes (PV) d −1 and then decreased to 0.1 PV d −1 after 100 PV of flow. Nitrate concentrations decreased from 10.8 mg L −1 (NO3 –N) to trace levels through NO3 − reduction to NH4 + using ZVI alone and through denitrification using OC. Observations from the mixture of ZVI and OC suggest a combination of NO3 − reduction and denitrification. Up to 71% of input SO4 2− (24.5 ± 3.5 mg L −1 ) was removed in the column containing OC, and >99.7% of the input ClO4 − (857 ± 63 μg L −1 ) was removed by the OC‐ and (ZVI + OC)‐containing columns as the flow rate was maintained at 0.1 PV d −1 . Nitrate and ClO4 − removal followed first‐order and zero‐order rates, respectively. Nitrate >2 mg L −1 (NO3 –N) inhibited ClO4 − removal in the OC‐containing column but not in the (ZVI + OC)‐containing column. Sulfate did not inhibit ClO4 − degradation within any of the columns.